A private American blood bank, bought last week by the Department of Health to ensure contamination-free supplies to the NHS has repeatedly had to recall its products, The Independent on Sunday can reveal. In one case, it shipped blood that had not been tested for viruses such as HIV, and in another, it distributed plasma that was hepatitis C positive.

The DoH bought Life Resources for £50m to get plasma for haemophiliacs and patients with burns or immune disorders. Since 1998 plasma has been shipped from the United States, due to the risk of UK plasma being contaminated by CJD, the human form of mad cow disease. Life Resources owns 24 plasma supply firms in the US.

But there have been five instances in the past five years when its companies have recalled plasma. These include an incident in 2000 when plasma was taken from a donor who was at increased risk of CJD; an incident in 1998 when a batch included material from an "unsuitable donor"; and in 1999, a donor was in prison and had tattoos, which should disqualify donors.

And, in 1996 one of the subsidiaries, DCI Biologicals Inc, New Mexico, received a warning from the US regulator, the Food and Drug Administration, that rules had been breached after a shipment of plasma tested positive for hepatitis C, and as not tested for HIV. In America, unlike Britain, people are paid for donating plasma.

The DoH said all plasma was checked for viruses in the UK, and was also heat-treated to inactivate any viruses. The DoH said all the companies' facilities had been inspected prior to purchase.

But the events add weight to a campaign by The Haemophilia Society, which wants those who have the disease to be given artificially-made plasma products, after a series of scandals where they were infected through contaminated plasma. It lists the UK as the worst in a league of 17 developed countries for providing safe treatment for haemophilia.

Late last month, a warning went out to haemophiliacs in Scotland and Ireland saying they were at risk of contracting CJD, because a donor in the 1980s had later developed the disease. In the 1970s and early 1980s many haemophiliacs were infected with hepatitis and HIV.